Drum



Oct. 14, 1941. G. M. RoalsoN 2,259,268

DRUM

Filed April l, 1959 G'EoeGE M. Ro/saw,

Patented Oct. 14, 1941 UNITED STATES PATENT OFFICE DRUM George M. Robison, Highland Park, Calif.

Application April 1, 1939, Serial No. 265,437

10 Claims.

This invention relates to improvements in drums, particularly kettle drums and the like, and has for an object the provision of improved means for varying the tension of the drum head.

Another object of the invention is to provide improved mechanism for varying the tension of the drum head irrespective of the position of adjustment of the drum upon its support.

VA further object of the invention involves the provision of improved means for adjusting the tension of the drum head and for maintaining said tensioning means in adjusted position.

Another object of the invention is to provide a drum having operating mechanism which can be readily assembled and dismantled.

.Still another object of the invention is to provide drum head tensioning means, some of which are contained within and carried by the drum body for removal therewith as a unit from there is shown a form in the drawing accom' `panying and forming part of the present specification. This form will now be described in de-y tail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

In the drawing:

Figure 1 is a sectional-elevational view of a drum structure embodying the present invention.

Figure 2 is a fragmentary vertical section showing certain portions of the invention on an enlarged scale.

Figure 3 is a section on an enlarged scale, taken as indicated by line 3-3 of Figure 1; and, Figure 4 is a section on an enlarged scale, taken as indicated by line 44 of Figure 3.

Referring with more particularity to the drawing, the present invention is shown as being applied to a drum of the kettle or tympani type. lThe drum body, generally designated B, includes aY shell I0, which may be spherical in contour or of a kettle form, and a saucer-like member II providing a seat I2 receiving the lower portion of the drum shell. The upper end of the drum shell I is formed with a rounded annular rim I3 defining the drum opening I4. This opening is closed by a resonant head I5 bearing against the annular rim I3 as shown clearest in Figure 1.

The drum head may be formed of any one of the well-known materials or substances possessing the desired resonating characteristics.

The marginal portions of the resonating head or skin I5 are held between a pair of cooperative annular clamping rings or members I6 and I 'I surrounding the upper end of the drum shell. The outer ring I1 is provided with a ange I8 extending inwardly over the ring I6 in bearing relation with the head I5. The tautness or tension in the drum head may be varied through the combined movement of the cooperative clamping rings I 6 and I1 axially of the drum body. Downward movement of these rings will stretch the head I5 over the annular rim I3 to increase its tautness.

Some of the instrumentalities for effecting movement of the clamping rings are supported by, and contained within, the drum shell I0. They include a plurality of members I9 xedly secured to, and depending from, the outer ring I1 at circumferentially spaced intervals. The lower ends of these members are pivotally connected by pins 23 to lever members 24 extending through slots 25 in the shell portion I0 of the drum body. Each of the levers 24 is fulcrumed by a pin 25 between a pair of lugs 21 secured to the interior of the shell at opposite sides of the openings 25. The inner extremities of the lever members 24 are pivotally ccnnected by pins 30 to a ring or spider member 3| which threadedly receives the upper end of an operating rod 32 extending between said spider and the lower` portion of the drum body (Figures l and 2). In the form shown, the rod 32 is maintained centrally or coaxially of the drum shell through its connection with the spider 3I.

Upward movement of the rod 32 will move the levers 24 about their fulcrums 26 to urge the members I9 and the associated clamping rings I6 and I'I downwardly, stretching the drum head over the annular rim I3 whereby to increase its tautness. Conversely, movement of the rod 32 downwardly will eiect a movement of these parts upwardly to reduce the tension of the drum head.

The drum shell I!! and tension` varying instrumentalities carried thereby are all removable as a unit from the seat l2 of the saucer-like member or support II. This is accomplished by providing the member I I with an externally threaded portion 35 extending into the shell interior through an openingA 36 in the bottom of the shell and receivable in an internally threaded nut or Thus, the shell and its associated tension varying instrumentalities may be removed from or mounted on the seat I2 of the member I I through rotation of the shell I0, made possible by the threaded connection between the nut or member 31 secured thereto and the extension 35 on the member Il,

For convenience in playing the instrument, it is sometimes desirable to position the drum body so that its playing head is inclined. In the form of the invention shown in the drawing, this is accomplished by providing a pivotal connection between the member Il of the drum body and a supporting member or standard S mounting said drum body. The pivotal connection is shown as including a pair of spaced lugs 39 depending from ,39 and45 whereby to form a pivotal mounting for the drum body to4 permit its angular adjustment. Means is provided for adjustingy the drum yangularly and positively maintaining it in adjusted position. This means includes a threaded rod 45 pivotally connected by a pin 46 to the Vmember II, to one side of the pivotal connection between said member and the standard S. This rod 45 extends downwardly through an opening ,41 in an arm 48 extending outwardly from the upper end of the standard S. A pair of thumb screws 49 and 50 are threadedly secured to the rod 45 o n opposite sides of the arm 48. When the upper thumb screw 49 is rotated downwardly on the rod 45, its engagement with the upper;

surface of the arm 48 moves the rod'upwardly through the opening 41 and causes a tilting of l the drum body about the axis of the pivotal connection and in the direction of the arrow (Figure in their adjusted positions. Obviously, reverse Arotation of the thumb screws will permit movement of the rod and drum body toward normal position where the drum head is horizontally disposed.

The means for operating the tension varying instrumentalities mounted on and contained within the drum shell, includes a lever 53 ful- -crumed by a pin 54 between a pair of lugs 55 depending from the member Il. The inner end of `the lever 53 extends between the spaced lugs 4i) on the standard S and is pivotally connected by a pin B to the lower end of a pilot pin or rod 51 `which extends upwardly through an opening'58 in the saucer-like member or support II. The upper end of said rod or pin is provided with a reduced portion 59 which is adapted to extend into a pocket or hollow end 69 of the rod 32 when the drum shell is mounted on the seat I2 of the member II. A shoulder BI defined by the reduced end 59 is adapted to abut the lower end of the rod 32 and lift the same upon upward movement of the pin 51, to operate the head tensioning instrumentalities in a tension increasing direction. This latter movement of the pin 51 and other head tensioning instrumentallties is effected upon downward movement of the outer end of the lever 53 to which the pin 51 is pivotally connected- Movement of the various tensioning instrumentalities in a tensioning increasing direction is opposed by the tension developed in the drum head, so that said instrumentalities are The lower thumb screw 50 can be corre-. Aspondingly adjusted upwardly into engagement `with the lower surface of the arm 48 to form a stop and positively hold the rod and drum body urged in a tension decreasing direction upon release of pressure on the outer end of the lever 53. Obviously, the end of rod 32 is maintained in abutment with the shoulder 6I on the pin 51 which is urged downwardly, causing upward movement of the outer end of the lever 53. Movement of the tensioning instrumentalities in a tension decreasing direction is assisted by the action of gravity on the rod 32 and the portions of the levers 24 extending into the drum shell I0.

Assurance is had that the reduced end 59 of of a foot pedal 65 or lever, pivotally connected at one end as at 55a to one leg 51 of the standard S, its other end being connected with the lever 53 through. the linkage 6,4. It is preferable to provvide adjustable linkage between the lever .5.3

and foot pedal in order to compensate for angular adjustment of the drum. Accordingly, the linkage is made in two sections 66 and 61, the section l 61 being pivotally connected at one end to the foot pedal 65 through a pivot bolt 68 and having recesses 69 at spaced intervals along its length. The other section SB is pivotallyconnected at one end as at 66a, to theV outer extremity of the lever 53, and carries at its lower end an element 10 telescoping over the link section 61 and having an adjustable set Yscrew 1I engageable with the recesses 89 in the link mem.- ber 61 for holding the link members againstrelative longitudinal movement.

It will be obvious how the tension in the drum head I5 may be varied at will through the application of varying degrees of pressure on the operating member or pedal 65, since these members are interconnected through the linkage 64, lever 53, pin 51, rod 32, levers 24, members I9, and cooperative clamping rings I5 and I1.

An important aspect of the invention comprises means lfor maintaining thervarious vadjusted tensions in the drum head. This isv ac.- complished by the provision of instrumentalities for automatically locking the foot pedal 65 in adjusted position. Such means includes a rod or strap 15 pivotally connected at its Vlower end.- as at 16 to the leg 61 of the support S, and extending upwardly betweena guide or stirrup element 11 and a cooperative cam 18 carried at the upper end of the foot pedal 65.' The cam 18 is in the form of a sleeve eccentrically xed on a shaft 19 revolubly mounted in opposed sides 65a and 65h of the pedal. Said shaft also provides a pivotal mounting for the sides 11a and 11b of thestirrup 11 so as to permit self adjustment between the stirrup and the strap 15 when the pedal 65 is adjusted to different angular positions. The cam 18 is normally urged into clamping relation with the strap 15 by a coil spring 89 having one `of its ends 8! acting against the upper edge of the pedal side 551) and its other end 82 acting against the underside of an operating element 19a secured to and extending upwardly from the shaft 19. This latter member preferably extends slightly above the foot engaging surface of the pedal so that it may be conveniently depressed (by the -foot of the operator to relieve the clamp# ing action of the cam and permit angular adjustment of the pedal.

I claim:

l. In a drum, a drum body, supporting means pivotally mounting said body, a drum head for the drum body, means for varying the tension of said head comprising an operating rod, means connecting said rod to said drum head, a lever fulcrumed on said body, means connecting said lever to said rod, a manually operable lever mounted on said supporting means, and an adjustable link connecting said lever to said manually operable lever.

2. In a drum, a drum body, supporting means pivotally mounting said body, a drum head for the drum body, means for varying the tension of said head comprising an operating rod, means connecting said rod to said drum head, a lever fulcrumed on said body, means connecting one end of said lever` to said rod, a manually operable lever mounted on said supporting means, and a linkage connecting said levers, said linkage including relatively slideable elements movable longitudinally with respect to each other whereby to adjust the eective length of said linkage.

3. In a drum, a drum body, supporting means pivotally mounting said body, a drum head for the drum body, means for varying the tension of said head comprising a lever fulcrumed on said body, means connecting said lever to the drum head, a pedal, a support for said pedal, a link connecting said pedal and lever, a rod mounted for pivotal movement on said support and slideably related with said pedal, cam means rotatably carried by said pedal and having means clamping said rod thereto, and an arm fixed to said camy means, said arm being adjacent; said pedal to permit convenient control of said pedal and cam means by the foot of an operator.

4. In a drum, a drum body, supporting means pivotally mounting said body, a drum head for the drum body, means for varying the tension of said head comprising an operating rod, means connecting said rod to Said drum head, a lever fulcrumed on said body, means connecting one end of said lever to said rod, a manually operable lever mounted on said supporting means, a link connecting the other end of said lever to said manually operable lever, and means for varying the length of said link.

5. In a drum, a drum body, a drum head for said drum body, means for varying the tension of said drum head comprising an operating rod, means connecting said rod to the drum head, a lever, supporting means pivotally mounting said lever, means connecting said lever` to said operating rod, means connecting said lever to the drum head, a rod pivoted to the supporting means, and clamping means adjustably connecting said lever to said rod, whereby said lever can be maintained in different positions of adjustment.

6. In a drum, a drum body, a drum head for said drum body, means for varying the tension of said drum head comprising an operating rod, means connecting said rod to the drum head, a

lever, supporting means pivotally mounting said lever, means connecting said lever to said operating rod, means connecting said lever to the drum head, a manually operated lever, a link connecting said iirst mentioned lever to said manually operated lever, means pivotally supporting said manually operated lever, a rod pivoted to the supporting means, and clamping means adjustably connecting said manually operated lever to said rod, to maintain it in different positions of adjustment.

7. In a drum, a drum body, a drum head for said drum body, means for varying the tension of said drum head comprising a lever, supporting means pivotally mounting said lever, means connecting said lever to the drum head, a manually operated lever, a link connecting said first mentioned lever to said manually operated lever, means supporting said manually operated lever, a rod carried by sai-d last mentioned supporting means slideably related with said manually operated lever, and a clamp carried by said manually operated lever and engageable with said rod for securing the rod and manually operated lever together.

8. 'I'he combination as defined in claim 7 wherein said clamp includes a rotatable cam carried by said manually operated lever and engageable with said rod for clamping it to said lever.

9. A drum which comprises a drum shell, a support carrying said shell having a threaded extension, a threaded portion on said shell for receiving said threaded extension, for securing said shell to the support, a drum head on said shell, a rod having a bore therein in said shell, means operative upon movement of said rod away from the support to increase the tension of the drum head, a second rod extending into the extension, spring means centering said second rod within said extension, means piloting said second mentioned rod within the bore of the rst mentioned rod, said rods having corresponding parts to transmit pushing forces from one rod to another, and operating means on sai-d support for moving said second mentioned rod in a direction away from the support to actuate said rst mentioned rod, to increase the tension of the drum head.

10. A drum, which comprises a drum shell, a support carrying said shell, means for detachably securing said shell to said support, a drum head on said shell, means for varying the tension of said head including a rod within the shell, means operative upon movement of said rod away from the support to increase the tension of the drum head, a second rod carried by said support and detachably abutting said first mentioned rod, an operating means on said support moving said second mentioned rod in a direction away from the support and maintaining it in position, to actuate said rst mentioned rod to increase and maintain the tension of the drum head.

GEORGE M. ROBISON. 

